Wiper blade

ABSTRACT

A wiper blade ( 18   a ) has a rubber holder ( 22 ) for holding a blade rubber ( 21 ). This rubber holder ( 22 ) has a connection block ( 24 ) coupled to a wiper arm and two sub-holders ( 25 ) fixed on both sides of the connection block ( 24 ), and the sub-holders ( 25 ) each has two rod-shaped spring members ( 27 ) curved with curvature radii smaller than that of a front glass and 11 holder pieces ( 26 ) fixed to these rod-shaped spring members ( 27 ) in a longitudinal direction at a predetermined interval. Further, this rubber holder ( 22 ) is formed so that the two sub-holders ( 25 ) are coupled to each other via the connection block ( 24 ) in the longitudinal direction.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is entitled to the benefit of and incorporates byreference essential subject matter disclosed in International PatentApplication No. PCT/JP2003/016117 filed on Dec. 16, 2003 and JapanesePatent Application No. 2003-060832 filed on Mar. 7, 2003.

FIELD OF THE INVENTION

The present invention relates to a wiper blade for wiping a windshieldglass face of a vehicle.

BACKGROUND OF THE INVENTION

In a vehicle such as an automobile, a wiper apparatus is provided toensure a visual field of a driver by wiping attached matters such asrain, snow, bugs, or droplets from preceding cars, which have beenadhered on a windshield glass such as a front glass. The wiper apparatusgenerally has a wiper arm swung by an electric motor and a wiper bladeattached to a tip portion of the wiper arm, wherein a wiping operationis conducted by the wider blade reciprocating on the windshield.

As the wiper blade used in such a wiper apparatus, there has been knownthe wiper blade in which the blade rubber directly contacting with thefront glass is directly attached to a flat leaf spring member formed ofan elastic member such as a steel plate, for example, as shown inJapanese Patent Laid-Open Publication No. 6-340249. In this case, theflat leaf spring member is formed to curve at a curvature radius smallerthan that of the front glass, so that the flat leaf spring member iselastically deformed by a pressing force applied from the wiper arm todisperse the pressing force in a longitudinal direction of the bladerubber.

In such a wiper blade, however, the flat leaf spring member is formedwith a longitudinal dimension equal to that of the blade rubber and intoa curved shape, so that when the wiper blade with a blade length of, forexample, 700 mm or so is manufactured, the flat leaf spring memberbecomes lengthy accordingly. Therefore, it is feared that: when the flatleaf spring members are carried into a work site, their returnable boxesgrow in size; due to decreasing of the packed number of them or thelike, efficiency in physical distribution aspects is lowered; and whenthe flat leaf spring members are processed, they are deformed due tointerference with a die or molding machine in some cases. That is,handling them has not been easy.

Furthermore, the windshield glasses provided to the vehicles often havedifferent curvatures depending on types of the vehicles due to theirdesign or the like. In contrast, since a distribution pressure of theblade rubber to the windshield glass is determined based on acharacteristic of the flat leaf spring member in such a wiper blade, thewiper blade using the flat leaf spring member with a predeterminedcharacteristic can generate a distribution pressure effective on only awindshield glass with a specific curvature. Accordingly, since the wiperblade using an exclusive flat leaf spring member is set for each vehicletype, it becomes necessary to prepare various kinds of flat leaf springmembers different in characteristic, so that manufacturing the wiperblades different in characteristic has become complicated.

An object of the present invention is to facilitate the manufacturing ofthe wiper blade.

Another object of the present invention is to make it easy tomanufacture the wiper blades different in characteristic.

BRIEF SUMMARY OF THE INVENTION

A wiper blade according to the present invention, which is attached to awiper arm provided swingably to a vehicle to perform a swinging motionon a windshield glass and wipes said windshield glass, wherein aplurality of elastic members elastically deformable in a directionperpendicular to said windshield glass are each attached integrally to ablade rubber contacting with said windshield glass and are coupled in alongitudinal direction.

The wiper blade according to the present invention is such thatsub-holders provided with holding portions for holding said blade rubberto said elastic members are coupled in the longitudinal direction.

The wiper blade according to the present invention is such that two ofsaid sub-holders are coupled via a connection block connected to saidwiper arm.

The wiper blade according to the present invention is such that aplurality of holding pieces respectively provided with said holdingportions, and a rod-shaped spring member coupling said holding pieces inthe longitudinal direction at a predetermined interval are provided tosaid sub-holders.

The wiper blade according to the present invention is such that elasticforces of said elastic members are made different in the longitudinaldirection of said blade rubber.

A manufacturing method of a wiper blade according to the presentinvention, the wiper blade having a blade rubber contacting with awindshield glass and a rubber holder for holding said blade rubber andattached to a wiper arm swingably provided to a vehicle to wipe saidwindshield glass, comprises: a sub-holder forming step of forming aplurality of sub-holders each having a holding portion holding saidblade rubber and being elastically deformable in a directionperpendicular to said windshield glass; a sub-holder coupling step ofcoupling said plurality of sub-holders in the longitudinal direction toform said rubber holder; and a blade-rubber attaching step of attachingsaid blade rubber to said rubber holder.

The manufacturing method of a wiper blade according to the presentinvention is such that said sub-holder forming step includes: aspring-member forming step of forming a rod-shaped spring member into apredetermined curved shape; and a holding-piece fixing step of fixing aplurality of holding pieces each having said holding portion to saidrod-shaped spring member in the longitudinal direction at apredetermined interval.

According to the present invention, since the longitudinal dimension ofeach of the elastic members constituting the wiper blade becomes short,carrying and handling them become facilitated and the manufacturing ofthe wiper blade can be easily carried out.

Also, according to the present invention, since the length of theelastic member or sub-holder becomes short, the returnable box used whenthese members are carried during the manufacturing time is reduced insize and the packed number of them can be increased, so that theefficiency in the physical distribution aspects in manufacturing thewiper blade can be improved.

Furthermore, according to the present invention, by combining thesub-holders different in characteristic, many kinds of wiper bladesdifferent in characteristic can be manufactured easily.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an explanatory diagram schematically showing a wiper apparatusprovided with a wiper blade according to an embodiment of the presentinvention.

FIG. 2A is a partially broken front view showing details of a DR-sidewiper blade shown in FIG. 1, and FIG. 2B is a front view showing arubber holder shown in FIG. 2A.

FIG. 3 is a perspective view showing details of the rubber holder shownin FIG. 2B.

FIG. 4 is a sectional view taken along line A-A in FIG. 2A.

FIGS. 5A to 5D are explanatory views showing manufacturing steps of theDR-side wiper blade.

FIG. 6 is an explanatory diagram showing a combination of sub-holdersdifferent in characteristic.

DETAILED DESCRIPTION OF THE INVENTION

As shown in FIG. 1, a wiper apparatus 13 is provided to a vehicle 11 inorder to wipe rain, droplets from preceding cars, or the like attachedto a front glass 12 serving as a windshield glass and ensure a visualfield for a driver.

The wiper apparatus 13 has: a driver-seat-side, i.e., DR-side wiper arm15 a, which is fixed to a wiper shaft 14 a rotatably supported to thevehicle 11 and is swingably provided to the vehicle 11; and similarly afront-passenger-seat-side, i.e., AS-side wiper arm 15 b, which is fixedto a wiper shaft 14 b rotatably supported to the vehicle 11 and isswingably provided to the vehicle 11. These wiper shafts 14 a, 14 b arecoupled to a wiper motor 17 via a link mechanism 16, and when the wipermotor 17 is actuated, the wiper arms 15 a, 15 b are swung within apredetermined angular range.

A driver-seat-side, i.e., DR-side wiper blade 18 a is attached to a tipof the DR-side wiper arm 15 a, and a front-passenger-seat-side, i.e.,AS-side wiper blade 18 b is attached to a tip of the wiper arm 15 b. Therespective wiper arms 15 a, 15 b have spring members such as springsunshown incorporated therein and the respective wiper blades 18 a, 18 b,to which pressing forces from the wiper arms 15 a, 15 b are applied, areelastically brought in contact with the front glass 12. When the wiperarms 15 a, 15 b swing, the wiper blades 18 a, 18 b perform swingingmotions on the front glass 12 in wiping ranges 12 a, 12 b between anupper reversing position and a lower reversing position positioned at alower end of the front glass 12, thereby wiping the front glass 12.

Thus, although the DR-side wiper blade 18 a and the AS-side wiper blade18 b are provided to the vehicle 11, these wiper blades 18 a, 18 b havethe same structure basically. Only the DR-side wiper blade 18 a will betherefore explained below.

FIG. 2A is a partially broken front view showing details of the DR-sidewiper blade shown in FIG. 1, and FIG. 2B is a front view showing therubber holder shown in FIG. 2A. FIG. 3 is a perspective view showingdetails of the rubber holder shown in FIG. 2B, and FIG. 4 is a sectionalview taken along A-A line in FIG. 2A.

As shown in FIG. 2A, the DR-side wiper blade 18 a (hereinafter called“wiper blade 18 a”) has a blade rubber 21 directly contacting with thefront glass 12 and a rubber holder 22 for holding this blade rubber 21,and is curved with a curvature radius smaller than the smallestcurvature radius in the wiping range of the front glass 12, namely, acurvature radius at the lower reversing position, in a state in whichthe wiper blade is separated from the front glass 12, i.e., a naturalstate.

As shown in FIG. 2B, a fin 23 made of, for example, hard rubber or thelike is attached to the rubber holder 22 so that air resistance thereofcan be reduced. A connection block 24 is provided at an almost centralportion of the rubber holder in a longitudinal direction thereof, andone side and the other side of the connection block 24 are provided withsub-holders 25, respectively.

As understood also from FIG. 3, the sub-holder 25 has a plurality of(for example in this embodiment, 11) holding pieces 26 and tworod-shaped spring members 27 serving as elastic members, and has astructure in which these holding pieces 26 are connected by therod-shape spring members 27 at predetermined intervals in a longitudinaldirection.

The holding pieces 26 are called “bridging members” or “elements”, andeach is formed into a C-shaped section having a base end wall portion 26a and a pair of side wall portions 26 b approximately perpendicular tothis base end wall portion 26 a, as shown in FIG. 4. Each side wallportion 26 b is provided with a holding portion 26 c, and the bladerubber 21 is held by the holding portions 26 c of the respective holdingpieces 26.

The rod-shaped spring members 27 are formed so that their sections areeach a circular and they are curved with a curvature radius smaller thanthat of the front glass 12, and they are arranged to be displaced in adirection of moving when the wiper blade 18 a performs a wipingoperation on the front glass 12, namely, in a wiping direction. As shownby one-dotted chain lines in FIG. 3, a plurality of crank portions 27 aeach bent in a crank fashion are formed in the rod-shaped spring members27 at predetermined intervals, and the respective holding pieces 26 arefixed to the corresponding crank portions 27 a on the side wall portions26 b. Since the holding pieces 26 are fixed by the rod-shaped springmembers 27, the holding portions 26 c for holding the blade rubber 21are provided to the rod-shaped spring members 27. The holding pieces 26are fixed to the crank portions 27 a, so that the rod-shaped springmembers 27 are connected to each other by the holding pieces 26 so as tohave predetermined rigidity in a wiping direction and become elasticallydeformable in a direction perpendicular to the front glass 12. That is,the sub-holders 25 become elastically deformable in a directionperpendicular to the front glass 12 because the rod-shape spring members27 are elastically deformed.

One of the sub-holders 25 is such that crank portions for connection 27b formed on one end sides of the rod-shaped spring members 27 are fixedto one end side of the connection block 24. The other of the sub-holders25 is such that the crank portions for connection 27 b formed on one endsides of the rod-shaped spring members 27 are fixed to the other endside of the connection block 24. Thus, the rubber holder 22 has astructure in which the two sub-holders 25 are coupled via the connectionblock 24 in the longitudinal direction. By coupling the sub-holders 25,the rod-shaped spring members 27 in the respective sub-holders 25 arecoupled in the longitudinal direction.

Meanwhile, the blade rubber 21 has a base portion 21 a and an edgeportion 21 b contacting with the front glass 12 to perform the wiping,and has the same shape as that of a blade rubber used in a wiper bladeof a tournament type having been known since conventionally. As qualityof material for the blade rubber 21, natural rubber, chloroprene rubber,or the like is used, and so as to have merits of respective materials, amaterial obtained by blending natural rubber and chloroprene rubber isoften used. The blade rubber 21 is produced by performing an extrusionmolding of these materials, and has the same sectional shape in itslongitudinal direction. Vertebras 28 formed into flat plates areattached to both side face portions of the base portion 21 a of theblade rubber 21, and the blade rubber 21 is such that a predeterminedelastic force is applied in a direction perpendicular to the front glass12 by the vertebras 28. The base portion 21 a is engaged with theholding portions 26 c of the respective holding pieces 26, so that theblade rubber 21 is held by the rubber holder 22.

A clip 31 is provided in the connection block 24, and the wiper blade 18a is connected to the DR-side wiper arm 15 a by the clip 31. A pressingforce from the DR-side wiper arm 15 a is applied to the rubber holder 22by the connection block 24. When the pressing force from the wiper arm15 a is applied to the connection block 24, the respective sub-holders25 are elastically deformed in conformity with the curvature of thefront glass 12, whereby the wiper blade 18 a is deformed so that thelongitudinal-entire blade rubber 21 contacts with the front glass 12.That is, the rod-shaped spring members 27 are elastically deformed, dueto the pressing force from the wiper arm 15 a, so that the rubber holder22 follows up the curvature of the front glass 12. Reaction forces ofthe rod-shaped spring members 27 due to the elastic deformation aretransmitted to the holding pieces 26 c, whereby the rubber holder 22creates a force for pressing the blade rubber 21 on the front glass 12.The vertebras 28 are attached to the blade rubber 21, so that when thepressing force of the wiper arm 15 a is applied to the rubber holder 22,the elastic forces of the vertebras 28 are applied to the blade rubber21 in addition to the reaction forces of the rod-shaped spring members27. Thereby, the reaction forces of the rod-shaped spring members 27discontinuously applied to the blade rubber 21 in the longitudinaldirection are corrected by the elastic forces of the vertebras 28, sothat a pressure distribution of the blade rubber 21 to the front glass12 is uniformized in the longitudinal direction. Thus, the pressingforce from the wiper arm 15 a is dispersed by the rod-shaped springmembers 27 and the vertebras 28 and applied to the blade rubber 21, andthe blade rubber 21 contacts with the front glass 12 to have apredetermined distribution pressure characteristic.

FIGS. 5A to 5D are explanatory views showing manufacturing steps of theDR-side wiper blade, and FIG. 6 is an explanatory view showing acombination of the sub-holders different in characteristic.

Next, a manufacturing method for such a wiper blade 18 a will beexplained.

In a sub-holder forming step, first, the plurality of sub-holders 25 aremanufactured. The sub-holder forming step includes a spring-memberforming step and a holding-piece fixing step. As shown in FIG. 5A, inthe spring-member forming step, the rod-shaped spring member 27 isformed into a predetermined bent shape by a pressing work and is formedinto such a shape as to have the plurality of crank portions 27 aarranged at predetermined intervals. At that time, a wire diameter orcurvature radius of the rod-shape spring member 27, the number of crankportions, and the like are set depending on the specification of thewiper blade.

Next, as shown in FIG. 5B, in the holding-piece fixing step, 11 holdingpieces 26 are fixed to the two rod-shaped spring members 27 at thepredetermined intervals in the longitudinal direction. In this case,since the hard resin material is injection-molded into the respectivecrank portions 27 a of the rod-shaped spring members 27 arranged in anunshown die, the respective holding pieces 26 are formed in a state ofbeing fixed to the rod-shaped spring members 27. Thus, the sub-holderforming step is performed by the spring-member forming step and theholding-piece fixing step, and the sub-holders 25 are formed by thesesteps. The sub-holders 25 formed at this time have characteristicscorresponding to those of the rod-shaped spring members 27 formed in thespring-member forming step.

Next, as shown in FIG. 5C, in a sub-holder coupling step, the twosub-holders 25 are coupled in the longitudinal direction, whereby therubber holder 22 is formed. In this case, by arranging the twosub-holders 25 in the longitudinal direction so as to be disposed in theunshown die and by injection-molding the hard resin material into thecrank portions for connection 27 b formed at the one ends of therod-shaped spring members 27, the connection block 24 is formed betweenthese sub-holders 25. That is, in the sub-holder coupling step, thecrank portions for connection 27 b provided in the rod-shaped springmembers 27 of the respective sub-holders 25 are both fixed to theconnection block 24, so that the sub-holders 25 are coupled via theconnection block 24 in the longitudinal direction.

As shown in FIG. 5D, finally, as a blade-rubber attaching step, theblade rubber 21 is assembled to the holding portions 26 c provided tothe respective holding pieces 26, and a fin 23 is fixed to an outercircumferential face of the rubber holder 22 by an adhesive, whereby thewiper blade 18 a is completed.

Thus, in the wiper blade 18 a, the rubber holder 22 is formed so thatthe two sub-holders 25 formed in the sub-holder forming step are coupledin the longitudinal direction in the sub-holder coupling step, so thatthe rod-shaped spring members 27 in moving from the spring-memberforming step to the holding-piece fixing step and the respectivesub-holders 25 in moving from the sub-holder forming step to thesub-holder coupling step can be reduced in length. Accordingly, handlingof the rod-shaped spring members 27 or the sub-holders 25 in thesub-holder forming step and the sub-holder coupling step becomes easy,so that the manufacturing of the wiper blade 18 a is made easy. Sincethe length of the rod-shaped spring member 27 or the sub-holder 25becomes short, a depth of an arc due to curving becomes small, so thatthe handling involved in being disposed in or taken out from the die isfacilitated and the rod-shaped spring member 27 and the sub-holder 25can be prevented from being deformed by interfering with the die ormolding machine.

Since the length of the rod-shaped spring member 27 or the sub-holder 25becomes short, the returnable box used in carrying these members duringa manufacturing time is reduced in size. Further, since the packednumber of them can be increased, efficiency in the physical distributionaspects when the wiper blade 18 a is manufactured can be improved.

Furthermore, in the wiper blade 18 a, the two sub-holders 25 are coupledby the sub-holder coupling step and the rubber holder 22 is formed, sothat if a plurality of sub-holders different in characteristic aremanufactured in the sub-holder forming step, many kinds of rubberholders, i.e., the wiper blades different in characteristic can bemanufactured easily in the sub-holder coupling step by combining thesesub-holders. Incidentally, the characteristic of the wiper blade is setbased upon a wire diameter, an elastic force, a curvature level or thelike of the rod-shaped spring member and indicates a characteristic of adistribution pressure of the blade rubber, which occurs when the wiperblade contacts with the front glass.

For example, as shown in FIG. 6, since the same sub-holder 25 as thesub-holder 25 shown in FIG. 2B is fixed to one side of the connectionblock 24 and concurrently a sub-holder 32 different in characteristicfrom the sub-holder 25 is fixed to the other side of the connectionblock 24, a rubber holder different in characteristic from the rubberholder 22 can be manufactured easily. In this case, the sub-holder 32 issuch that an elastic coefficient of the rod-shaped spring member 27 ismade different in the longitudinal direction of the blade rubber 21 bysetting the intervals L1 to L4 between the holding pieces 26 on its tipside to be gradually increased toward the tip side of the sub-holder 32,whereby the characteristic of the rubber holder can be changed.Incidentally, in FIG. 6, members corresponding to the members previouslydescribed are denoted by the same reference numerals.

Thus, in the wiper blade 18 a, by combining the sub-holders 25 and 32different in characteristic from each other, many kinds of wiper blades18 a different in characteristic can be manufactured easily.

Needless to say, the present invention is not limited to the aboveembodiment and can be variously modified without departing from the gistthereof. For example, in the above embodiment, the sub-holder 25 has theplurality of holding pieces 26 and the rod-shaped spring members 27connecting these holding pieces 26 in the longitudinal direction at thepredetermined intervals, but is not limited to this case and may be usedas a sub-holder having the flat leaf spring member to which the bladerubber 21 can be directly attached.

According to the above embodiment, the rod-shaped spring member 27 isused for coupling the holding pieces 26 in the longitudinal direction,but is not limited to this case and the sub-holder 25 may be formed byusing a plurality of elastic members that couple only the holding pieces26 adjacent to each other. As such an elastic member, for example, aplate member or the like formed into a flat plate may be proposed.

Furthermore, in the above embodiment, the two sub-holders 25 are coupledvia the connection block 24 in the longitudinal direction, but are notlimited to this case and two or more sub-holders formed further shortmay be coupled in the longitudinal direction.

Moreover, in the above embodiment, the present invention is applied tothe wiper blade 18 a of the wiper apparatus 13 of a tandem type, but isnot limited to this case and may be applied to the AS-side wiper blade18 b or another wiper blade used in a wiper apparatus of another typesuch as an opposite wiping type.

The present invention can be applied in manufacturing many kinds ofwiper blades corresponding to the windshield glasses different incurvature or size.

While the present invention has been illustrated and described withrespect to a particular embodiment thereof, it should be appreciated bythose of ordinary skill in the art that various modifications to thisinvention may be made without departing from the spirit and scope of thepresent invention.

1. A wiper blade attached to a wiper arm provided swingably to a vehicleto perform a swinging motion on a windshield glass and wipe saidwindshield glass, the wiper blade comprising: two sub-holders coupled ina longitudinal direction via a connection block connected to said wiperarm; wherein a plurality of holding pieces respectively provided withholding portions for holding a blade rubber, and a rod-shaped springmember coupling said plurality of holding pieces in the longitudinaldirection at a predetermined interval are provided at said sub-holders;wherein said connection block is formed by injection-molding of hardresin material; and wherein one of said sub-holders is fixed to one endside of said connection block by one end side of the rod-shaped springmember and the other of said sub-holders is fixed to the other end sideof said connection block by one end side of the rod-shaped springmember.